A steel structure fabricated in China is normally produced to Chinese GB standards unless the contract says otherwise. Overseas projects frequently reference EN, ASTM, AS or another national system. The gap between the two is managed through documents, not through assumptions.
Most quality disputes in this area come from one of two mistakes: assuming that a similar-looking grade can be substituted, or leaving the welding and inspection standard undefined while specifying only the material standard.
The standards that need to be named
Material is only one of the standards in play. A complete specification normally names each of the following.
| Subject | Common options |
|---|---|
| Design code | GB 50017, EN 1993 (Eurocode 3), AISC 360, AS 4100 |
| Material grade | GB/T 700, GB/T 1591, EN 10025, ASTM A36, ASTM A572 |
| Welding and fabrication | GB 50661, EN 1090-2, AWS D1.1 |
| Bolting | GB/T 1228 series, EN 14399, ASTM A325 / A490 |
| Corrosion protection | ISO 12944, ISO 1461, project specification |
| Tolerances and inspection | GB 50205, EN 1090-2, AISC 303, project ITP |
Why an equivalent grade is not a substitute
Grade comparison tables are useful for orientation, and nothing more. Two grades that sit on the same line of a comparison table can differ in chemistry, impact class, thickness limits and the permissible design stress that the engineer has already used.
- The impact class changes design behaviour in cold regions, and it is not captured by the strength number alone.
- Thickness-dependent properties change with plate thickness, so the same grade behaves differently in a 10 mm and a 40 mm section.
- Certification evidence differs. A mill certificate to one standard does not automatically satisfy an inspector working to another.
- The engineer of record may have based the design on a specific standard and a specific reduction factor.
What to send when drawings are in a different system
- The design code and the edition or year of the code
- The material standard and grade, including the impact class
- The welding standard, and whether any welder qualification certificates are required
- The inspection and testing requirements, including the inspection and test plan if one exists
- The coating specification with the corrosion category and required dry film thickness
- The tolerance standard, and the acceptance criteria for dimensional checks
- Any requirement for third-party inspection, and which organisation will attend
Documentation to expect with the shipment
Documentation is where a standards decision is proved. For structural steel shipments, the package normally includes:
- Mill test certificates traceable to heat numbers, matching the approved material list
- Inspection records for dimensional checks, welds and coating
- The packing list, with piece marks that match the erection drawings
- Loading photographs, so the condition at loading can be compared with the condition on arrival
This guide describes general practice for steel structure projects. It is not a design, and it does not replace the specification or the engineer responsible for your project.